The scalability and stability of electrocatalysts is one of the biggest challenges for their practical applicability. In this context, Co3O4 nanoparticles conformally coated on a light weight, 3D and highly conducting carbon cloth are fabricated using an easily synthesized cobalt hexadecylthiolate complex as ink. This method is especially useful for large-scale production as the complex is synthesized in large quantities and coated on 3D substrates by a simple dip-coating method. The optimum loading of the catalyst is achieved through a layer-by-layer (LbL) assembly of a cobalt hexadecylthiolate complex via repeated dip coating of the carbon cloth electrode in the solution. The Co3O4/CC undergoes electrochemical oxidation and converts to CoOOH as an active species and acts as a highly efficient electrocatalyst with optimized loading. The Co3O4-16/CC with 16 times dip coating exhibits remarkable stability over 24 h with an overpotential of 300 mV at 10 mA cm−2 and a Tafel slope of 77.06 mV dec−1. The electrocatalytic activity of Co3O4-16/CC prepared by LbL coating is better than conventional Co3O4 and comparable to IrO2 and RuO2 electrocatalysts with the future possibility of commercial-scale production at lower cost. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim